1. Field of the Invention
The present invention relates to wireless communication and more specifically to a method and apparatus of reporting measurement logged in a wireless communication system.
2. Related Art
3GPP (3rd generation Partnership Project) LTE (Long Term Evolution), which is an advanced version of UMTS (Universal Mobile Telecommunications System), is not being introduced as 3GPP release 8. 3GPP LTE uses OFDMA(orthogonal frequency division multiple access) on downlink and SC-FDMA(Single Carrier-frequency division multiple access) on uplink. 3GPP LTE adopts MIMO (Multiple Input Multiple Output) having a maximum of 4 antennas. Recently, 3GPP LTE-A (LTE-advanced) which is an advanced version of 3GPP LTE is now in discussion.
MDT (Minimization of Driving Tests) is for service providers to perform a test by using a terminal rather than a vehicle for the purpose of coverage optimization. Coverage varies depending on the position of a base station, arrangement of adjacent buildings, and a user's usage environment. Accordingly, service providers need to conduct a periodic driving test which requires high costs and resources. In MDT, a service provider measures coverage using a terminal.
MDTs may be categorized into logged MDTs and immediate MDTs. In the logged MDT, a terminal performs MDT measurement and transfers a logged measurement to a network at a specific time. In the immediate MDT, a terminal performs MDT measurement and when a condition is met, then transfers the measurement to a network. The logged MDT carries out MDT measurement in an RRC idle mode while the immediate MDT does in the RRC connection mode.
A user equipment performs logging irrespective of whether what is currently being measured is essential. As a result, duplicate log information may be included in the log stored in the user equipment. Due to such duplicate information, the size of the logged measurement increases, and wireless resources used for reporting the logged measurement and the memory may be inefficiently used.